Premier Dies Corporation “standard” tolerance for flatness/straightness of a fixed slot die half is less than .0002” (5 microns) maximum variation across the entire width of the die. For flexible lip slot dies the “standard” tolerance for flatness/straightness per die half is less than .0003” (7.6 microns) maximum variation across the entire width of the die. If desired and depending upon the die design, we are capable of manufacturing to a flatness tolerance of .5 microns maximum variation across the entire width of a die half.